O2491 AUTOLOGOUS BONE MARROW FOR NON UNIONS

Abstract

Tissue engineering can be deþned as any effort to create or induce the formation of a speciþc tissue in a speciþc location through the selection and manipulation of cells, matrices, and biologic stimuli. The biologic concepts and the biochemical and biophysical principles on which these efforts are based have become a rapidly evolving þeld of biomedical research. More importantly, tissue engineering is becoming a clinical reality in the practice of orthopaedic surgery, providing patients and physicians with an expanding set of practical tools for effective therapy. The efþcacy of all current clinical tools depends entirely on the cells in the grafted site, particularly the small subset of stem cells and progenitor cells that are capable of generating new tissue. The current author reviews a series of key biologic concepts related to the rational design and selection of cells in contemporary bone grafting and tissue engineering efforts. The functional paradigms of stem cell biology are reviewed and sources for autogenous stem cells for connective tissues are discussed. Finally a technique to obtain stem cells for the treatment of non unions is described.

We included 48 patients: 38 cases of post-traumatic non union (12 of them with infection); 4 non unions following arthrodesis (3 knees, 1 tibiotarsal); 4 cases with Illizarov technique; 2 patients with congenital abnormalities. The source of bone marrow was the iliac crest. The marrow was reduced in volume (50 ml) in order to increase the concentration in stem cells by elimination of erythrocytes and polynuclear cells. The number of nucleated cells was counted in the marrow transplanted and the þbroblast colony forming cells (CFU-F) and the osteoblast colony forming cells (CFU-Ost) were cloned to appreciate the number and the activity of progenitor in the marrow transplanted.